Integrated Chemical and Biological Microsystems for Discovery and Process

Development

Klavs F. JensenDepartments of Chemical Engineering and

Materials Science and EngineeringMassachusetts Institute of Technology

Cambridge, MA 02139, USAkfjensen@mit.edu

MIT

Microsystems and Drug Development

Discovery – hits

Lead

Optimization

Trials

Product

Robotics, arrays, and combinatorial approaches have revolutionized the discovery process

Lead optimization, process development remain challenges

Images: beckmancoulter.com, tecan-us.com, appliedbiosystems.com

MIT

Reactor

ENIAC

Biochemical and Chemical Microsystems

Microfabrication has revolutionized electronic and optical information technologyMicrofluidic systems are emerging for analysis (microTotal Analysis Systems)Instrumented microchemical systems could revolutionize chemical research and production by• speeding up time to production with

reduced need for upfront capital investment

• obtaining chemical information (e.g., kinetics) and optimize chemical processes more efficiently

• providing timely, efficient synthesis platforms

• providing safe and environmentally friendly research and production tools

MIT

~2000

micro Total Analysis Systems (mTAS)

Laboratory equipment and facilities have changed Workflow - individual, separate operations - has not evolved as rapidly

~1930

Air Lines

THERMALREACTION

DROP METERING

SAMPLE LOADING

GEL LOADING

PC Board

GlassSilicon

Wire Bonds

DETECT

Burns et al. Science, 282, 484 (1998)

SEPARATE

www.caliper.com

µµµµTAS integrate fluid manipulations, reactions, separations, and analysisUltimately information management must also be included

MIT

µµµµTotal Analysis Systems - Biological Applications

Applications • DNA identification• Assays • Synthesis

Advantages:• small volumes of

expensive reagents,• parallel operation,• integration of flow,

reactions, separation, and detection

• integration with information management

J.D. Harrison (Univ. Alberta)

www.gyrosmicro.comwww.nanogen.com

www.micronics.com

Andreas Manz, Imperial College

MIT

Why Micro Systems?Reduced length scales• Improved heat and mass transfer • Increased surface to volume ratio• Smaller reagent volume

Microfabrication• Controlled contacting of reagents • Integration of sensors and actuators• Ease of replication

Chemical research and development• Safe handling of reactive, hazardous chemistry• Small amounts of expensive materials • Ease of performing experiments on new chemistry• New methods for high throughput screening • Scalable manufacturing by “numbering up”

• Chem/bio information and faster development

-0.002

0.038

0.078

0.118

0.158

0.198

0.238

490 530 570 610Wavelength (nm)

Abs

orba

nce

MIT

Fabrication Methods

Si - MEMSLIGA (lithography + electroplating)Lamination of patterned glass,ceramic, polymer, and metal layersRapid Prototyping (soft lithography)Micromachining (CNC, µµµµEDM, …)Si advantages:• Si and coatings compatible with chemicals• wide range of tools for micromachining• ease of integration of actuation and sensing

Combination of new techniques and materials will be needed to realize advanced designs

50 µm

PDMS

G.M. WhitesidesHarvard

MIT

Microreactor for Liquid Phase Chemistry Integrated Heat Exchangers and Temperature Sensors

Thin-Film Temperature

Sensor

U = 1500 W/m2°C

Heat Exchanger

air gapcooling fluid

reaction mixture

300µm

Optical fibervisible

spectroscopy

SimulationExperiment

~ 20 ms mixing time

Low Re flows - mixing by diffusion

Accurate computational fluid dynamics predictions

MIT

Microreactors Integrated with IR Spectroscopy Provide Rapid Optimization and Reaction Parameters

5 mm

0

0.1

0.2

0.3

0.4

0.5

0.6

17201745177017951820Wavelength (wavenumbers)

Abs

orba

nce

2.43 s4.86 s48.6 s81.0 s243 s

17911738

H2OO

Cl

O

OH→ + HCl+

SiliconMIR

crystal

PDMS channels

epoxy connectors

0.5 cm

1000 1200 1400 1600 1800Wavenumbers (cm-1)

Abso

rban

ce

5 x 10-3

Acetic acid,

Ethyl acetate Ethanol

MIT

Microreactors for PhotochemistryPotential advantages:• Continuous flow• Enhancement of mass and heat transfer• Large surface area-to-volume ratio• No deposition on window

O

+

HOH

H

O

O

hν (366 nm) +O

Model reaction: benzopinacol formation

UV Lamp

Conversion Immediately Following Irradiation

0%

10%

20%

30%

40%

50%

0 2 4 6 8 10 12flowrate (µ l/min)

conv

ersi

on

Subsequentdark reactions

MIT

Multiphase Microreactors

Traditional multiphase packed-bed reactors:KLa = 0.001 - 0.08 s-1

Dominated by mass transfer

G

L

L

G

Microreactor KLa = 2-15 s-1

Mass transfer improved 100X

36-38 µmParticle size

100µµµµm

MIT

Multiphase Microreactors - Hydrogenation

kaK

]H[Rate

iL

SAT

η11

2

+=

Traditional multiphase packed-bed reactors:KLa = 0.001 - 0.08 s-1

10-8

10-7

10-6

10-5

10-4

0.001 0.01 0.1 1 10 100

KLa (s-1)

Rea

ctio

n R

ate

(mol

/s/g

cat

alys

t)

Typical KL a values

Cyclohexene Hydrogenation

Microreactor KLa = 2-15 s-1

Mass transfer improved 100X

Microreactor Results

G

L

L

G

MIT

Handling Reactive and Toxic Chemistry

0

0.2

0.4

0.6

0.8

1

50 100 150 200 250 300

Con

vers

ion

Temperature (°C)

On demand synthesis of phosgene

- 10 multichannel reactors: ~ 2 g/min.

R N C O

R NH2 + COCl2 R NHCOCl-HCl

R NHCONH R

-HClR N C OR N C OR N C O

R NH2 + COCl2 R NHCOCl-HCl

R NH2 + COCl2R NH2 + COCl2 R NHCOClR NHCOCl-HCl

R NHCONH RR NHCONH R

-HCl

Point-of-use synthesis of isocyanate

Phosgene synthesis CO + Cl2 ���� COCl2 (∆∆∆∆H = -109 kJ/molShipping and storage restrictions ���� Distributed production

MIT

Microreaction Technology for Direct Fluorination

NH2NaNO2/HCl

HBF4

NN+

BF4− ∆

F

+ N2 + BF3

R

F

R

+ F2

R

+ HF

H

(l) (g) (l)(l)

Hazardous HF and F2

Heat management- low temperature- diluted reactants

Obstacles for direct fluorination scale-up

Multi-step processLow yieldsNot suitable for all aromatics

Current routes to fluorinated aromatics

Pyrex glass

Interchannel wall

Silicon

Nickel

Ni coating makes device compatible with F2 and HF

Microreactor for direct fluorination

Room temperature operation gives similar

results as experiments at very low temperature

Microreactors expand operating regimes –allowing reactive chemistry to be performed safely

under optimal conditions

MIT

Gas Phase CatalystGas Phase CatalystTest SystemTest System

0.55 m0.55 m

0.65

m0.

65 m

Demonstration of Scale-Up and Integration

Replace walk-in chemical fume hood space with desktop systemSystem integration raise significant challenges

x 2

Jim Ryley et al.

DuPont

David Quiram

MIT

MIT

µµµµFluidic Integration with Soft Lithography

PMDS based systems are flexible, but not compatible with most organic solventsApplications are primarily for biological systems

Peristaltic Pump Quake et al.

Science, 288, 113 (1999)3D Microfluidic NetworksWhitesides et al. Anal. Chem.72, 3158 (2000)

Microfluidic Arrays Whitesides et al. Anal. Chem.

73 5207 (2000)

fluid in

fluid out

air pressure

MIT

µµµµFluidic Systems for Biological Applications

Soft lithography methods provide opportunities for realizing microsystems with unique properties for biological applications

Microfabricated Fluorescence-Activated Cell Sorter

Quake et al. Nature Biotech. 17, 110 (1999)

Patterning Cells in Laminar FlowWhitesides et al.

Acc. Chem. Res. 33, 841 (2000)

MIT

Example – Isolation of Mitochondria

Would like to explore role of specific organelles in cell signaling

Conventional approaches• potential artifacts with mechanical

or chemical cell lysis• large samples and time

consuming• study of average of large

population (~106)Microsystems• novel cell lysis and organelle

separation approaches• small cell populations (~103)• probe a subpopulation • integrate functions

MIT

Lysing by Electroporation (HT-29 cells)

nucleusnucleus

Intact cell Dissolving membrane Bare nucleus

Electroplated gold structure

Channel on glass substrate

SU-8 wall

Gold thin film electrodeBond pad200 µm

50 µm

µµµµFluidic electroporation device

MIT

IsoElectric Focusing of Mitochondria

end of channel

middle of channel

beginning of channelpH gradient

Flow

MIT

This experiment used full content of cell lysate and whole cells.

Other fractions are not labeled, therefore not visible.

Mitochondria and cells were in a homogeneous mixture at the start of the channel.

Separation of mitochondria from whole cells in lysateachieved.

Separation of Mitochondria from Cells

Whole cells

Mitochondria fraction

Enhanced contrast

100 µm

MIT

Integrated Device Concept

Integrated microfluidic devices could enable study of organelle and subcelluar response to stimuli

Lysing unit Rough separation unit Fine separation unit

Buffer inlet

Sample inlet / outlet

Stimulus Image selection

Micro Facs

Buffer inlet

Sample inlet / outlet

Waste

Sample

Further analysis

MIT

Microfermentation Techniques

Conventional approaches• Analytical techniques limiting• Large parameter spaces• Expensive fermentation units - time consuming experiments

Small instrumented bioreactors - µµµµfermentors• Parallel investigations of multiple cell cultures in well defined

physiological states (steady state)• High throughput screen for function• Linking and incorporation of functional genomics• Optimization and translation into large scale processes

MIT

Opportunities

Integration of electronics, optics, and chemistry provide significant opportunities

Sensors• chemical spectroscopy - mass, IR, UV, NMR ….• biology - molecular, cells, tissue

Functional devices based on chemistry • chemical fuel based power devices• pharmacology• consumer products

Production systems • chemical synthesis units for on-demand, on-site production• materials synthesis• synthesis of nucleotides, proteins, sugars …

MIT

Acknowledgements

The microreactor teamMartin A. Schmidt

Leonel Arana, Sameer Ajmera, Cyril Delattre, Nuria De Mas, AleksFranz, Tamara Floyd, Rebecca Jackman, Matthew Losey, Hang Lu, and David Quiram

The staff of the Microsystems Technology Laboratories

Langer LabSorger Lab

MicroChemical Systems Technology CenterDARPA, DuPont, and Novartis Foundation

MIT

Recent Relevant Publications1. K.F. Jensen, Microreaction engineering - is small better?, Chem. Eng. Sci. 56, 293-303 (2001).2. R.J. Jackman, T.M. Floyd, R. Ghodssi, M.A. Schmidt, and K.F. Jensen, Microfluidic systems with on-

line UV detection fabricated in photodefinable epoxy, J. Micromechanical and Microengineering. 11263-279 (2001).

3. M.W. Losey, M.A. Schmidt and K.F. Jensen, Microfabricated multiphase packed-bed reactors: Characterization of mass transfer and reactions, Ind. Eng. Research, 40, 2555-2562 (2001).

4. S.K. Ajmera, M.W. Losey, and K.F. Jensen, Microfabricated packed-bed reactor for distributed chemical synthesis: The heterogeneous gas phase production of phosgene as a model chemistry, Am. Inst. Chem. Eng. J. 47, 1639-1647 (2001).

5. S.L. Firebaugh, K.F. Jensen, M.A. Schmidt, Miniaturization and integration of photoacoustic detection with a microfabricated chemical reactor system, J. Microelectromechanical Systems, 10 232-238 (2001).

6. N. de Mas, R. J. Jackman, M. A. Schmidt, K F. Jensen, Microchemical systems for direct fluorination of aromatics, Proceedings Fifth International Conference on Microreaction Technology (IMRET5), Strasbourg, France, May 2001

7. H.Lu, M.A. Schmidt, and K. F. Jensen, Photochemical reactions and on-line UV detection in microfabricated reactors, Lab-on-a-Chip, 1, 22-28 (2001)

8. H. Lu, R.J. Jackman, S. Gaudet, M. Cardone, M.A. Schmidt, and K.F. Jensen, “Microfluidic devices for cell lysis and isolation of organelles,” MicroTotal Analysis Systems (mTAS) 2001, J.M. Ramsey & A. van den Berg (Eds.), Kluwer Academic, Dordrecht (2001). pp. 297-8

9. T. M. Floyd, M.A. Schmidt, K.F. Jensen, “A silicon microchip for infrared transmission kinetics studies of rapid homogeneous liquid reactions,” ibid pp. 277-9

10. R.J. Jackman, K. T. Queeney, M.A. Schmidt, and K.F. Jensen, “Integration of multiple internal reflection (MIR) infrared spectroscopy with silicon-based chemical microreactors,” ibid pp. 345-6

11. D.J. Quiram, J.F. Ryley, J. Ashmead, R.D. Bryson, D.J. Kraus, P.L. Mills, R.E. Mitchell, M.D. Wetzel, M.A. Schmidt, and K.F. Jensen, “Device level integration to form a parallel microfluidic reactor system,” ibid pp. 661-3